Renal sugar transport, and its relationship to the tissue metabolism, will be investigated: 1. The localization and mechanism of insulin effect on renal sugar transport and metabolism will be studied comparing normal, hypoinsulinemic (streptozotocin-treated) and hyperinsulinemic (obese) rats. In vitro, a new method permitting the simulataneous determination of glucose oxidation and gluconeogenesis in suspensions of renal tubules will be used. The localization of the effect of insulin (and cyclic nucleotides) will be investigated using perfused portions of mammalian nephron (in cooperation with Dr. Z. Agus). 2. Experiments on the mechanism of the insulin-like effect of ouabain and orthovanadate on sugar entry and metabolism in rat adipocytes will be continued. Normal hypo- and hyper-insulinemic rats will be used as experimental models, including studies on the effect of experimental conditions on the incorporation of 32P into membrane and cellular protein. 3. The mechanism (particularly the possibility of delta micron H plus as the driving force) and localization of the renal secretion of 2-deoxy-D-galactose will be studied in mammalian and flounder nephron, by the perfusion technique in vitro (cooperation with Drs. Agus and Byenbach).